Block splitting assembly and method

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 13/072,308, filed Mar. 25, 2011, which is a continuation of U.S. patent application Ser. No. 12/952,742, filed Nov. 23, 2010, issued as U.S. Pat. No. 7,967,001, which is a continuation of U.S. patent application Ser. No. 11/926,491, filed Oct. 29, 2007, issued as U.S. Pat. No. 8,006,683, which is a divisional of U.S. patent application Ser. No. 11/297,121, filed Dec. 7, 2005, now abandoned, which is a continuation application of U.S. patent application Ser. No. 11/030,739, filed Jan. 6, 2005, issued as U.S. Pat. No. 7,066,167, which is a continuation application of U.S. patent application Ser. No. 09/884,795, filed Jun. 19, 2001, issued as U.S. Pat. No. 6,918,715, which is a continuation-in-part of U.S. patent application Ser. No. 09/691,864, filed Oct. 19, 2000, issued as U.S. Pat. No. 6,910,474, which is a continuation-in-part of U.S. patent application Ser. No. 09/330,879, filed Jun. 11, 1999, issued as U.S. Pat. No. 6,321,740, which applications are hereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

The invention relates generally to manufacture of masonry block. More specifically, it relates to equipment and processes for the creation of decorative faces on masonry block. Even more specifically, the invention relates to equipment and processes for producing roughened textures and the appearance of weathered or rock-like edges on masonry block, as well as to masonry blocks that result from such equipment and processes.

BACKGROUND OF THE INVENTION

It has become rather common to use concrete masonry blocks for landscaping purposes. Such blocks are used to create, for example, retaining walls, ranging from comparatively large structures to small tree ring walls and garden edging walls. Concrete masonry blocks are made in high speed production plants, and typically are exceedingly uniform in appearance. This is not an undesirable characteristic in some landscaping applications, but it is a drawback in many applications where there is a demand for a “natural” appearance to the material used to construct the walls and other landscaping structures.

One way to make concrete masonry blocks less uniform, and more “natural” appearing, is to use a splitting process to create a “rock-face” on the block. In this process, as it is commonly practiced, a large concrete workpiece which has been adequately cured is split or cracked apart to form two blocks. The resulting faces of the resulting two blocks along the plane of splitting or cracking are textured and irregular, so as to appear “rock-like”. This process of splitting a workpiece into two masonry blocks to create a rock-like appearance on the exposed faces of the blocks is shown, for example, in Besser's U.S. Pat. No. 1,534,353, which discloses the manual splitting of blocks using a hammer and chisel.

Automated equipment to split block is well-known, and generally includes splitting apparatus comprising a supporting table and opposed, hydraulically-actuated splitting blades. A splitting blade in this application is typically a substantial steel plate that is tapered to a relatively narrow or sharp knife edge. The blades typically are arranged so that the knife edges will engage the top and bottom surfaces of the workpiece in a perpendicular relationship with those surfaces, and arranged in a coplanar relationship with each other. In operation, the workpiece is moved onto the supporting table and between the blades. The blades are brought into engagement with the top and bottom surfaces of the workpiece. An increasing force is exerted on each blade, urging the blades towards each other. As the forces on the blades are increased, the workpiece splits (cracks), generally along the plane of alignment of the blades.

These machines are useful for the high-speed processing of blocks. They produce a rock-face finish on the blocks. No two faces resulting from this process are identical, so the blocks are more natural in appearance than standard, non-split blocks. However, the edges of the faces resulting from the industry-standard splitting process are generally well-defined, i.e., regular and “sharp”, and the non-split surfaces of the blocks, which are sometimes in view in landscape applications, are regular, “shiny” and non-textured, and have a “machine-made” appearance.

These concrete masonry blocks can be made to look more natural if the regular, sharp edges of their faces are eliminated.

One known process for eliminating the regular, sharp edges on concrete blocks is the process known as tumbling. In this process, a relatively large number of blocks are loaded into a drum which is rotated around a generally horizontal axis. The blocks bang against each other, knocking off the sharp edges, and also chipping and scarring the edges and faces of the blocks. The process has been commonly used to produce a weathered, “used” look to concrete paving stones. These paving stones are typically relatively small blocks of concrete. A common size is 3: inches wide by 7: inches long by 2.2 inches thick, with a weight of about 6 pounds.

The tumbling process is also now being used with some retaining wall blocks to produce a weathered, less uniform look to the faces of the blocks. There are several drawbacks to the use of the tumbling process in general, and to the tumbling of retaining wall blocks, in particular. In general, tumbling is a costly process. The blocks must be very strong before they can be tumbled. Typically, the blocks must sit for several weeks after they have been formed to gain adequate strength. This means they must be assembled into cubes, typically on wooden pallets, and transported away from the production line for the necessary storage time. They must then be transported to the tumbler, depalletized, processed through the tumbler, and recubed and repalletized. All of this “off-line” processing is expensive. Additionally, there can be substantial spoilage of blocks that break apart in the tumbler. The tumbling apparatus itself can be quite expensive, and a high maintenance item.

Retaining wall blocks, unlike pavers, can have relatively complex shapes. They are stacked into courses in use, with each course setback a uniform distance from the course below. Retaining walls must also typically have some shear strength between courses, to resist earth pressures behind the wall. A common way to provide uniform setback and course-to-course shear strength is to form an integral locator/shear key on the blocks. Commonly these keys take the form of lips (flanges) or tongue and groove structures. Because retaining wall blocks range in size from quite small blocks (e.g. about 10 pounds and having a front face with an area of about 3 square foot) up to quite large blocks having a front face of a full square foot and weighing on the order of one hundred pounds, they may also be cored, or have extended tail sections. These complex shapes cannot survive the tumbling process. Locators get knocked off, and face shells get cracked through. As a consequence, the retaining wall blocks that do get tumbled are typically of very simple shapes, are relatively small, and do not have integral locator/shear keys. Instead, they must be used with ancillary pins, clips, or other devices to establish setback and shear resistance. Use of these ancillary pins or clips makes it more difficult and expensive to construct walls than is the case with blocks having integral locators.

Another option for eliminating the sharp, regular edges and for distressing the face of concrete blocks is to use a hammermill-type machine. In this type of machine, rotating hammers or other tools attack the face of the block to chip away pieces of it. These types of machines are typically expensive, and require space on the production line that is often not available in block plants, especially older plants. This option can also slow down production, if it is done “in line”, because the process can only move as fast as the hammermill can operate on each block, and the blocks typically need to be manipulated, e.g. flipped over and/or rotated, to attack all of their edges. If the hammermill-type process is done off-line, it creates many of the inefficiencies described above with respect to tumbling.

Accordingly, there is a need for equipment and a process that creates a more natural appearance to the faces of concrete retaining wall blocks, by, among other things, eliminating the regular, sharp face edges that result from the industry-standard splitting process, particularly, in such a manner that it does not slow down the production line, does not add costly equipment to the line, does not require additional space on a production line, is not labor-intensive, and does not have high cull rates when processing blocks with integral locator flanges or other similar features.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the invention, there is provided a masonry block with a block body that includes a top surface, a bottom surface, a front surface extending between the top and bottom surfaces, a rear surface extending between the top and bottom surfaces, and side surfaces between the front and rear surfaces. A locator protrusion is disposed on either the top or the bottom surface (preferably, the bottom surface). Further, the intersection of the front surface and the top surface define an upper edge, and the intersection of the front surface and the bottom surface defining a lower edge, and the front surface has been given a rock-like texture, and at least one of the upper edge and the lower edge are roughened (that is, distressed so as to not appear as sharp with well-defined, regular edges, but, rather, to appear to have been weathered, tumbled, or otherwise broken, irregular and worn).

In accordance with a second aspect of the invention, there is provided a wall that is formed from a plurality of the masonry blocks.

In accordance with another aspect of the invention, there is provided a masonry block formed from a molded workpiece. The masonry block comprises a block body that includes a top surface, a bottom surface, a roughened front surface extending between the top and bottom surfaces, a rear surface extending between the top and bottom surfaces, and side surfaces between the front and rear surfaces, wherein a portion of at least two of the surfaces is textured as a result of the action of the workpiece-forming mold.

In another aspect of the invention, a masonry block is provided that is produced from a molded workpiece that is split in a block splitter having a splitting line, the block splitter comprising a first splitting assembly that includes a plurality of projections disposed on at least one side of the splitting line. The projections are positioned so that they engage the workpiece during the splitting operation, whereby the masonry block includes at least one irregular split edge and surface produced by the first splitting assembly.

In accordance with another aspect of the invention, a method of producing a masonry block having at least one irregular split edge and surface is provided. The method comprises providing a masonry block splitter having a splitting line with which a masonry workpiece to be split is to be aligned, with the block splitter including a first splitting assembly that includes a plurality of projections disposed on at least one side of the splitting line. The projections are positioned so that they engage the workpiece during the splitting operation. A masonry workpiece is located in the masonry block splitter so that the workpiece is aligned with the splitting line, and the workpiece is split into at least two pieces using the splitting assembly.

In another aspect of the invention, a masonry block is provided that is produced from a molded workpiece that is split in a block splitter having a first splitting blade with a cutting edge and blade surfaces extending away from the cutting edge at acute angles and which are engageable with the workpiece during the splitting operation, whereby the masonry block includes at least one irregular split edge and surface produced by the first splitting blade.

In still another aspect of the invention, a splitting assembly for use in a block splitter is provided that comprises a splitting blade, and a plurality of projections mounted on the splitting blade on at least one side thereof. The projections and the blade are fixed relative to each other during a splitting operation to split a workpiece whereby the projections and the blade move simultaneously during the splitting operation.

These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages and objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying description, in which there is described a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

<figref idref="DRAWINGS">FIG. 1</figref> is a partial perspective view of a block splitting machine using the block splitter blade assembly of the invention.

<figref idref="DRAWINGS">FIG. 2A</figref> is a top plan view of one portion of a splitting blade assembly in accordance with the invention.

<figref idref="DRAWINGS">FIG. 2B</figref> is a top plan view of one portion of a splitting blade assembly also showing projections of various diameters positioned in a random manner.

<figref idref="DRAWINGS">FIG. 2C</figref> is a top plan view of one portion of a splitting blade assembly in accordance with a further alternative embodiment of the invention comprising projections which are random connected and unconnected panels.

<figref idref="DRAWINGS">FIG. 3</figref> is a side elevational view of an alternative embodiment of a projection in accordance with the invention.

<figref idref="DRAWINGS">FIG. 4A</figref> is a side elevational view of a further alternative embodiment of a projection in accordance with the invention.

<figref idref="DRAWINGS">FIG. 4B</figref> is a side elevational view of another alternative embodiment of the invention depicting projections of varying heights.

<figref idref="DRAWINGS">FIG. 5</figref> is a perspective view of a split workpiece (forming two masonry blocks), which was split using the splitter blade assembly of the invention.

<figref idref="DRAWINGS">FIG. 6</figref> is a top plan view of a masonry block split using the splitter blade assembly of the invention.

<figref idref="DRAWINGS">FIG. 7</figref> is a front elevational view of the masonry block depicted in <figref idref="DRAWINGS">FIG. 6</figref>.

<figref idref="DRAWINGS">FIG. 8</figref> is a partially sectioned end view of an alternative embodiment of a top splitter blade assembly.

<figref idref="DRAWINGS">FIG. 9</figref> is a partially sectioned end view of an alternative embodiment of a bottom splitter blade assembly.

<figref idref="DRAWINGS">FIG. 10</figref> is a top plan view of a portion of the bottom splitter blade assembly of <figref idref="DRAWINGS">FIG. 9</figref> with one arrangement of projections, shown in relation to a workpiece.

<figref idref="DRAWINGS">FIG. 11</figref> is a partially sectioned end view of another alternative embodiment of a bottom splitter blade assembly.

<figref idref="DRAWINGS">FIG. 12</figref> is a top plan view of a gripper assembly according to the present invention and a portion of the bottom splitter blade assembly of <figref idref="DRAWINGS">FIG. 11</figref> with another arrangement of projections, shown in relation to a workpiece.

<figref idref="DRAWINGS">FIG. 12A</figref> is an exploded view of the portion contained within line <b>12</b>A in <figref idref="DRAWINGS">FIG. 12</figref>.

<figref idref="DRAWINGS">FIG. 13</figref> is a top view of a mold assembly for forming the workpiece illustrated in <figref idref="DRAWINGS">FIG. 12</figref>.

<figref idref="DRAWINGS">FIG. 14</figref> is a perspective view of a masonry block that is split from a workpiece using top and bottom splitting blade assemblies of the type illustrated in <figref idref="DRAWINGS">FIGS. 8 and 11</figref>.

<figref idref="DRAWINGS">FIG. 15</figref> is a bottom plan view of the masonry block in <figref idref="DRAWINGS">FIG. 14</figref>.

<figref idref="DRAWINGS">FIG. 16</figref> is a side view of the masonry block of <figref idref="DRAWINGS">FIG. 14</figref>.

<figref idref="DRAWINGS">FIG. 17</figref> is a perspective view of an alternative embodiment of a masonry block that has been split according to the present invention.

<figref idref="DRAWINGS">FIG. 18</figref> illustrates a wall constructed from differently sized blocks that have been split according to the invention.

<figref idref="DRAWINGS">FIG. 19</figref> is a front view of a mold wall in which a single horizontal groove or channel has been cut in the wall close to the bottom of the wall.

<figref idref="DRAWINGS">FIG. 20</figref> is a sectional view of the mold wall shown in <figref idref="DRAWINGS">FIG. 19</figref> taken at line <b>20</b>-<b>20</b> to show the cross section of the groove.

<figref idref="DRAWINGS">FIG. 21</figref> is a top view of a hopper and partition plate for swirling the colors of the fill material.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Attention is now directed to the figures where like parts are identified with like numerals through several views. In <figref idref="DRAWINGS">FIG. 1</figref>, a conventional block splitting machine modified in accordance with the invention is depicted, in part, showing in particular the block splitter assembly <b>10</b>. Generally, block splitting machines suitable for practicing the present invention may be obtained from Lithibar Co., located in Holland, Mich. and other equipment manufacturers. In particular, the Lithibar Co. model 6386 was used in practicing the invention. The block splitter assembly <b>10</b> generally comprises a support table <b>11</b>, and opposed first <b>12</b> and second <b>22</b> splitting blade assemblies. The first splitting blade assembly <b>12</b> is positioned at the bottom of the block splitter <b>10</b> and, as depicted, includes a splitting blade <b>14</b> and a number of projections positioned on either side of and adjacent to the blade. In this case, the projections <b>16</b> are generally cylindrically-shaped pieces of steel, having rounded or bullet-shaped distal ends. The first splitting blade assembly <b>12</b> is adapted to move upwardly through an opening in the support table <b>11</b> to engage the workpiece <b>40</b>, and to move downwardly through the opening so that a subsequent workpiece can be positioned in the splitter.

The invention may be used with any variety of blocks molded or formed through any variety of processes including those blocks and processes disclosed in U.S. Pat. No. 5,827,015 issued Oct. 27, 1998, U.S. Pat. No. 5,017,049 issued May 21, 1991 and U.S. Pat. No. 5,709,062 issued Jan. 20, 1998.

An upper or second splitting blade assembly <b>22</b> may also be seen in <figref idref="DRAWINGS">FIG. 1</figref>. The second splitting blade assembly <b>22</b> also includes a splitting blade <b>24</b> and a plurality of projections <b>26</b> located on either side of the blade <b>24</b>. The second splitting blade assembly may be attached to the machine's top plate <b>30</b> through a blade holder <b>28</b>. The position of the workpiece <b>40</b>, (shown in phantom), within the block splitter may be seen in <figref idref="DRAWINGS">FIG. 1</figref>, in the ready-to-split position.

As can be seen in <figref idref="DRAWINGS">FIG. 2A</figref>, the splitting blade assembly <b>12</b> is generally comprised of a number of projections <b>16</b> positioned adjacent to the blade <b>14</b> and on either side of the blade <b>14</b>. As shown, the projections <b>16</b> on the first side of the blade are staggered in relationship to the projections <b>16</b>′ on the second side of the blade. The projections on either side of the blade may also be aligned depending upon the intent of the operator.

As can be seen in <figref idref="DRAWINGS">FIG. 2B</figref>, the projections <b>16</b> may be used without a splitting blade. The projections <b>16</b> may also be varied in diameter or perimeter, (if not round), and placed randomly on the splitting assembly <b>12</b>. Any number of ordered or random patterns of projections <b>16</b> may be created using regular or irregular spacing depending on the effect to be created in the split block.

<figref idref="DRAWINGS">FIG. 2C</figref> shows a further alternative embodiment of the invention where plates <b>16</b>″ are attached to either, or both, assemblies <b>12</b> and <b>22</b>. As can be seen, these plates may be configured in random order and left unconnected across the surface of the assembly <b>12</b>. The invention has been practiced using steel plates about four inches long welded to the assembly to provide a number of partially connected projections <b>16</b>″ about two inches high.

In splitting assemblies in which splitting blades are used, such as the splitting blades <b>14</b>, <b>24</b>, the splitting blades are arranged in coplanar relationship, and so as to engage the bottom and top surfaces of the workpiece <b>40</b> in a generally perpendicular relationship. The splitting blade <b>14</b> (and likewise the splitting blade <b>24</b>) define a splitting line SL, shown in <figref idref="DRAWINGS">FIG. 2A</figref>, with which the workpiece <b>40</b> is aligned for splitting. When splitting blades are not used, such as shown in <figref idref="DRAWINGS">FIG. 2B</figref>, the workpiece <b>40</b> is still aligned with the splitting line SL which is illustrated as extending generally through the center of the assembly <b>12</b>. In either event, block splitters conventionally have a splitting line SL, defined by splitting blades when used, with which the workpiece is aligned for splitting.

As shown in <figref idref="DRAWINGS">FIGS. 1, 2A and 2B</figref>, the projections <b>16</b> and <b>16</b>′ may have a rounded shape. However, the shape of the projections may also be pyramidal, cubic, or pointed with one or more points on the top surface of the projection. In <figref idref="DRAWINGS">FIGS. 2A, 2B and 2C</figref>, the relative position of the workpiece <b>40</b> is shown again in phantom outline.

Generally, the projections may have a diameter of about 2 to about 1.3 inches and may be attached to the blade assembly by welding, screwing or other suitable means. The height of the projections may be about 1.3 inches and varied about: of an inch shorter or taller depending upon the affect to be created in the block at splitting. Attaching the protrusions by threading or screwing, see <figref idref="DRAWINGS">FIGS. 8-9 and 11</figref>, allows easy adjustment of projection height.

The relative height of the projection and blade may also be varied depending upon the effect that is to be created in the block that is split from a workpiece according to the invention. Specifically, as can be seen in <figref idref="DRAWINGS">FIG. 3</figref> the relative height of the blade <b>14</b> may be less than the relative height of the projection <b>16</b>. Alternatively, as can be seen in <figref idref="DRAWINGS">FIG. 4A</figref> the relative height of the blade <b>24</b> may be greater than the height of the projections <b>26</b>. For example, we have found with the first splitting blade assembly <b>12</b> that X may range from about ⅛ to about ⅜ of an inch below or beyond the first blade <b>14</b>. With regard to the second splitting blade assembly <b>22</b>, X′ may range from about 1/16 to about ⅛ of an inch beyond the height of the plurality of the projections <b>26</b>.

Projections <b>16</b> such as those depicted in <figref idref="DRAWINGS">FIG. 2A</figref> have been found useful having a diameter of about 1 and ¼ inches and, when used with a blade <b>14</b>, having a height of about ⅛ of an inch below the blade in the first or lower assembly <b>12</b> and about ⅛ of an inch below the blade <b>24</b> in the second or upper assembly <b>22</b>. Overall, the height of the projections on either the lower assembly <b>12</b> or upper assembly <b>22</b> may vary up or down as much as about ⅜ of an inch relative to the height of the blade in either direction relative to the top of the blade, with the top of the blade being zero.

In operation, the workpiece <b>40</b> is generally centered in the block splitter and aligned with the splitting line SL according to known practices as seen in <figref idref="DRAWINGS">FIGS. 1 and 2A</figref>, B and C. The block splitter is then activated resulting in the first and second opposing splitting blade assemblies <b>12</b>, <b>22</b> converging on, and striking, the workpiece <b>40</b>. In operation, the first and second splitting blade assemblies may travel anywhere from about ¼ to about one inch into the top and bottom surfaces of the workpiece. The workpiece <b>40</b> is then split resulting in an uneven patterning on the split edges <b>46</b><i>a</i>, <b>46</b><i>b </i>and <b>46</b><i>a</i>′, <b>46</b><i>b</i>′ of the respective resulting blocks <b>42</b> and <b>44</b>, as illustrated in <figref idref="DRAWINGS">FIG. 5</figref>. As depicted, the workpiece <b>40</b> is split in two. However, it is possible and within the scope of the invention to split the workpiece into more than two pieces. It is also possible and within the scope of the invention to split the workpiece into a usable masonry block and a waste piece.

The distance traveled by the projections <b>16</b>, <b>26</b> into the workpiece may be varied by adjusting the limit switches on the block splitting machine and, in turn, varying the hydraulic pressure with which the splitting assemblies act. Generally, the splitting assemblies act on the block with a pressure ranging from about 600 to about 1000 psi, and preferably about 750 to about 800 psi.

As will be well understood by one of skill in the art, the splitting machine may include opposed hydraulically activated side knife assemblies (not shown) which impinge upon the block with the same timing and in the same manner as the opposed top and bottom assemblies. Projections <b>16</b>, <b>26</b> may also be used to supplement or replace the action of the side knives, as discussed below with respect to <figref idref="DRAWINGS">FIG. 12</figref>. For example, side knives similar to the upper splitting blade <b>24</b> shown in <figref idref="DRAWINGS">FIG. 8</figref> can be employed.

Closer examination of block <b>44</b> after splitting (see <figref idref="DRAWINGS">FIGS. 6 and 7</figref>) shows the formation of exaggerated points of erosion in the front, split surface <b>47</b> of the block <b>44</b>. With the block <b>44</b> depicted, both the first and second blade assemblies <b>12</b> and <b>22</b> comprised projections <b>16</b> and <b>26</b>, respectively. As a result, depressions <b>48</b> and <b>50</b> were formed at the upper and lower edges <b>46</b><i>a</i>, <b>46</b><i>b </i>of the front, split surface <b>47</b> of the block <b>44</b>, at the intersection with the upper <b>52</b> and lower <b>54</b> respective surfaces of the block <b>44</b>.

The magnitude of the indentations, <b>48</b> and <b>50</b>, or points of erosion is far greater than that which is caused by conventional splitting blades and may be varied by varying the prominence of the projections <b>16</b> and <b>26</b>, (height and size), relative to the height and thickness of the blade. In one embodiment of the invention, masonry block may be split with only a row or rows of projections <b>16</b> and <b>26</b> without a blade <b>14</b> and <b>24</b>.

Referring to <figref idref="DRAWINGS">FIGS. 8 and 9</figref>, alternative embodiments of a top splitting blade assembly <b>22</b>′ and bottom splitting blade assembly <b>12</b>′, respectively, are shown. It has been found that more massive blades <b>14</b>′, <b>24</b>′ having projections <b>16</b>, <b>26</b> thereon create a more desirable block face appearance. Blades <b>14</b>′, <b>24</b>′ include a central cutting edge <b>21</b>, <b>31</b>, respectively, and surfaces <b>19</b>, <b>29</b> extending outwardly therefrom. The tip of each cutting edge <b>21</b>, <b>31</b> defines the splitting line along which the workpiece will be split. Surfaces <b>19</b>, <b>29</b> extend away from the cutting edges <b>21</b>, <b>31</b> at relatively shallow angles, so that, as the blade assemblies converge during splitting, the surfaces <b>19</b>, <b>29</b> will engage the split edges of the workpiece. This engagement breaks, chips, distresses, or softens the split edges in an irregular fashion, and the distressing action can be enhanced by placing projections on the surfaces <b>19</b>, <b>29</b>, as desired. The surfaces <b>19</b>, <b>29</b> are preferably at an angle α between about 0° and about 30° relative to horizontal, most preferably about 23°.

Blades <b>14</b>′, <b>24</b>′ include projections <b>16</b>, <b>26</b> that are adjustable and removable. In this way, the same blade assembly can be used for splitting different block configurations by changing the number, location, spacing and height of the projections. Projections <b>16</b>, <b>26</b> are preferably threaded into corresponding threaded openings <b>17</b>, <b>27</b> for adjustment, although other height adjustment means could be employed. However, during a splitting action, the projections and the blades are in a fixed relationship relative to each other, whereby as the blade moves, the projections associated with the blade move simultaneously with the blade.

The projections <b>16</b>, <b>26</b> in this embodiment are preferably made of a carbide tipped metal material. In addition, the top surface of the projections <b>16</b>, <b>26</b> is jagged, comprising many pyramids in a checkerboard pattern. Projections such as these can be obtained from Fairlane Products Co. of Fraser, Mich. It will be understood that a variety of other projection top surface configurations could be employed. The height of the top surface of the projections is preferably a distance X′ below the tip of cutting edge <b>21</b>, <b>31</b>, most preferably 0.040 inch below. As discussed above with respect to other embodiments, the projections may extend further below, or some distance above, the top of the blade, within the principles of the invention. The projections shown are about ¾ inch diameter with a 10 thread/inch pitch, and are about 1.50 inches long. Diameters between about 0.50 and about 1.0 inch are believed preferable. The loose block material from the splitting process entering the threads, in combination with the vertical force of the splitting strikes, are considered sufficient to lock the projections in place. However, other mechanisms could be used to lock the projections in place relative to the blades during the splitting process.

As should be apparent from the description, the cutting edges <b>21</b>, <b>31</b> and the projections <b>16</b>, <b>26</b> are wear locations during the splitting process. The removable mounting of the projections <b>16</b>, <b>26</b> permits the projections to be removed and replaced as needed due to such wear. It is also preferred that the cutting edges <b>21</b>, <b>31</b> be removable and replaceable, so that as the cutting edges <b>21</b>, <b>31</b> wear, they can be replaced as needed. The cutting edges <b>21</b>, <b>31</b> can be secured to the respective blade <b>14</b>′, <b>24</b>′ through any number of conventional removable fastening techniques, such as by bolting the cutting edges to the blades, with the cutting edges <b>21</b>, <b>31</b> being removably disposed within a slot <b>25</b> formed in the blade as shown in <figref idref="DRAWINGS">FIG. 11</figref> for the blade <b>14</b>′.

The preferred top blade assembly <b>22</b>′ is about 2.5 inches wide as measured between the side walls <b>24</b><i>a</i>, <b>24</b><i>b </i>of the blade <b>24</b>′. The projections <b>26</b> extend perpendicularly from the blade surfaces <b>29</b> and therefore strike the working piece at an angle.

The preferred bottom blade assembly <b>12</b>′ is about 4.0 inches wide as measured between the side walls <b>14</b><i>a</i>, <b>14</b><i>b </i>of the blade <b>14</b>′. The projections <b>16</b> extend upwardly from shoulders <b>23</b> on opposite sides of the blade surfaces <b>19</b>. This configuration breaks away more material and creates a more rounded rock-like top edge of the resulting split block (the workpiece is typically inverted or “lips up” during splitting because the workpiece is formed in a “lips up” orientation that allows the workpiece to lay flat on what is to be the upper surface of the resulting block(s)).

The preferred bottom blade assembly <b>12</b>′ also includes adjustable and removable projections <b>16</b> extending upward from the blade surfaces <b>19</b>, as shown in <figref idref="DRAWINGS">FIGS. 11 and 12</figref>. In this case, the projections <b>16</b> extend perpendicular to the surfaces <b>19</b> and strike the workpiece at an angle. The projections <b>16</b> extending upward from the surfaces <b>19</b> and the projections extending upward from the shoulders <b>23</b> can be of different sizes as shown in <figref idref="DRAWINGS">FIG. 11</figref>, or of the same size as shown in <figref idref="DRAWINGS">FIG. 12</figref>.

The angling of the projections <b>16</b> on the surfaces <b>19</b> of the blade <b>14</b>′, and the angling of the projections <b>26</b> on the surfaces <b>29</b> of the blade <b>24</b>′, allows the projections <b>16</b>, <b>26</b> to gouge into the workpiece and break away material primarily adjacent the bottom and top edges of the resulting block, however without breaking away too much material. As described below in more detail with respect to <figref idref="DRAWINGS">FIG. 12</figref>, the bottom blade assembly typically contacts the workpiece after the top blade assembly has begun its splitting action. The initial splitting action of the top blade assembly can force the resulting split pieces of the workpiece away from each other before the bottom blade assembly <b>12</b>′ and the angled projections <b>16</b> can fully complete their splitting action. The vertical projections <b>16</b> on the surfaces <b>23</b> of the blade <b>14</b>′ help to hold the split pieces in place to enable the angled projections <b>16</b> to complete their splitting action. The vertical projections <b>16</b> also break away portions of the split pieces adjacent the bottom edges of the resulting block(s). Thus, the angled and vertical projections <b>16</b> on the bottom blade <b>14</b>′ function together to produce a rounded bottom edge on the resulting block, while the angled projections <b>26</b> on the blade <b>24</b>′ function to produce a rounded top edge on the resulting block.

In operation, the blade assemblies of <figref idref="DRAWINGS">FIGS. 8 and 11</figref> are preferably used together to split a workpiece, using the same cutting depth and hydraulic pressures described above. It will be understood that the bottom blade assembly could be used on top, and the top blade assembly could be used on the bottom.

Referring now to <figref idref="DRAWINGS">FIG. 10</figref>, a blade assembly according to <figref idref="DRAWINGS">FIG. 9</figref> is depicted in position for striking a workpiece <b>58</b>. The workpiece <b>58</b> comprises portions which will result in small <b>60</b>, medium <b>62</b> and large <b>64</b> blocks. The projections <b>16</b> are preferably placed at appropriate locations on the blade <b>14</b>′ to create the three blocks <b>60</b>, <b>62</b>, <b>64</b> when the workpiece <b>58</b> is split. For example, the projections <b>16</b> can be located as shown in <figref idref="DRAWINGS">FIG. 10</figref>. The upper blade assembly of <figref idref="DRAWINGS">FIG. 8</figref>, which can be used in conjunction with the blade assembly of <figref idref="DRAWINGS">FIG. 9</figref> to split the workpiece <b>58</b>, has similarly oriented projections except that they are closer to the splitting line SL defined by the cutting edge <b>31</b>. In this way, more rounded, rock-like edges on the resulting masonry blocks are formed in the splitting process.

The positioning of the projections on the blades <b>14</b>′, <b>24</b>′ can be used in conjunction with mold configurations that pre-form the workpiece <b>58</b> at pre-determined locations to better achieve rounded, rock-like corners. For example, the walls of the mold that are used to form the workpiece <b>58</b> in <figref idref="DRAWINGS">FIG. 10</figref> can include suitable contoured portions so as to form the contoured regions <b>59</b><i>a</i>, <b>59</b><i>b</i>, <b>59</b><i>c </i>in the workpiece <b>58</b>. The contoured regions <b>59</b><i>a</i>, <b>59</b><i>b</i>, <b>59</b><i>c </i>contribute to the formation of the rounded, rock-like corners when the workpiece <b>58</b> is split. Further information on the mold configuration that is used to create the workpiece <b>58</b> can be found in co-pending U.S. patent application Ser. No. 09/691,931, filed on Oct. 19, 2000, which is herein incorporated by reference in its entirety.

Referring now to <figref idref="DRAWINGS">FIG. 12</figref>, a gripper assembly <b>70</b> is shown in conjunction with a preferred workpiece <b>68</b> for use in forming a pair of blocks according to the invention. A bottom splitting blade assembly <b>12</b>′ according to <figref idref="DRAWINGS">FIG. 11</figref>, which is preferably used in combination with the top splitting blade assembly of <figref idref="DRAWINGS">FIG. 8</figref> to split the workpiece <b>68</b>, is also shown in relation to the workpiece <b>68</b>. <figref idref="DRAWINGS">FIG. 12A</figref> illustrates the portion contained within line <b>12</b>A in <figref idref="DRAWINGS">FIG. 12</figref> in greater detail. The workpiece <b>68</b> is illustrated in dashed lines for clarity.

Gripper assembly <b>70</b> is employed to assist with splitting certain types of larger block units. It is mounted via mounting head <b>71</b> on the existing side-knife cylinders of the splitting machine. Rubber shoes <b>72</b> are configured to conform to the corresponding outer surface of the workpiece <b>68</b>. Each gripper assembly <b>70</b> moves in and out laterally, as indicated by arrows, in order to grip the workpiece <b>68</b> from both sides. In the preferred design, assembly <b>70</b> is about 3.0 inches high and rubber shoes <b>72</b> are 50-100 Durometer hardness. The pressure applied by the hydraulic cylinders is the same as that for the upper and lower blades.

One benefit of this gripper assembly is improving the formation of rounded edges of a workpiece made by a bottom splitting blade assembly. A workpiece <b>68</b> is moved along the manufacturing line by positioning bar <b>80</b> in the direction of the arrow shown. During splitting, while the rear portion of the workpiece <b>68</b> is held in place by the bar <b>80</b>, the forward portion is free to move forward. Many splitting machines have a splitting action whereby the bottom blade assembly moves to engage the workpiece after the top blade assembly has touched the top of the workpiece. The initial cutting action of the top blade assembly can begin to move the forward portion forward before the bottom blade assembly has an opportunity to fully form a rounded edge on the forward block with for example projections <b>16</b> and/or blade surfaces <b>19</b>. The bottom blade assembly can also lift the workpiece <b>68</b>, which is undesirable for a number of reasons. By holding the workpiece <b>68</b> together during splitting, these problems are prevented.

Gripper assembly <b>70</b> can optionally include projections <b>16</b>, as shown in <figref idref="DRAWINGS">FIGS. 12 and 12A</figref>. Projections <b>16</b> are preferably positioned slightly inside the top and bottom edges of the workpiece <b>68</b> (four projections for each gripper assembly <b>70</b>) so when they strike the side of the workpiece <b>68</b>, more rounded block corners will be formed. The assembly <b>70</b> can also include a side knife contained within its central cavity <b>73</b>, having a blunt blade such as those described hereinabove, for forming rounded, rock-like side edges of the split blocks. It may be necessary to include an appropriate strength spring behind the side knife in order to get the desired action from the gripper and knife.

The preferred workpiece <b>68</b> is also formed to include contoured regions <b>74</b>, <b>75</b>, <b>76</b>, <b>77</b> at pre-determined locations to better achieve rounded, rock-like corners. For example, the walls of the mold that are used to form the workpiece <b>68</b> in <figref idref="DRAWINGS">FIG. 12</figref> can include suitable contouring so as to form the contoured regions <b>74</b>-<b>77</b> in the workpiece <b>68</b> (see <figref idref="DRAWINGS">FIG. 13</figref>). The contoured regions <b>74</b>-<b>77</b> contribute to the formation of the rounded, rock-like corners when the workpiece <b>68</b> is split. The contoured regions <b>74</b>-<b>77</b> preferably extend the entire height of the workpiece from the bottom surface to the top surface thereof.

The contoured regions <b>74</b>, <b>75</b> are best seen in <figref idref="DRAWINGS">FIG. 12A</figref>. It is to be understood that the contoured regions <b>76</b>, <b>77</b> are identical to the regions <b>74</b>, <b>75</b> but located on the opposite side of the workpiece <b>68</b>. The contoured regions each include a convex section <b>78</b> having a radius R and a linear section <b>79</b> that transitions into the side surface of the workpiece <b>68</b>. The shape of the contoured regions is selected to achieve satisfactory radiused corners on the block once the workpiece <b>68</b> is split. Satisfactory results have been achieved using a radius R of about 1.0 inch, a distance d₁between the intersection of the convex section <b>78</b> with the linear section <b>79</b> and the edge of the projection <b>16</b> of about 0.25 inches, a distance d₂between the intersection of the convex section <b>78</b> with the linear section <b>79</b> and the center of the projection <b>16</b> of about 0.563 inches, and a distance d₃between the closest points of the convex sections <b>74</b>, <b>75</b> of about 0.677 inches. Other dimensions could be used depending upon the end results sought.

<figref idref="DRAWINGS">FIG. 13</figref> illustrates a mold <b>84</b> that is used to form the workpiece <b>68</b>. The mold <b>84</b> is provided with two mold cavities <b>86</b><i>a</i>, <b>86</b><i>b </i>to permit simultaneous formation of a pair of workpieces <b>68</b> and ultimately four blocks. Other mold configurations producing a greater or smaller number of workpieces could be used as well. The walls of the mold <b>84</b> in each mold cavity include regions <b>88</b>-<b>91</b> that are shaped to produce the contoured regions <b>74</b>-<b>77</b>, respectively, on the workpiece <b>68</b>.

A masonry block <b>100</b> that results from a splitting process on the workpiece <b>68</b> using the splitting assemblies <b>12</b>′ and <b>22</b>′ of <figref idref="DRAWINGS">FIGS. 11 and 8</figref>, respectively, is shown in <figref idref="DRAWINGS">FIGS. 14-16</figref>. The masonry block <b>100</b> includes a block body with a generally flat top surface <b>102</b>, a generally flat bottom surface <b>104</b>, side surfaces <b>106</b>, <b>108</b>, a front surface <b>110</b> and a rear surface <b>112</b>. The words “top” and “bottom” refer to the surfaces <b>102</b>, <b>104</b> of the block after splitting and after the block is inverted from its lips-up orientation during splitting. In addition, the front surface <b>110</b> of the block <b>100</b> is connected to the side surfaces <b>106</b>, <b>108</b> by radiused sections <b>114</b>, <b>116</b>. The radiused sections <b>114</b>, <b>116</b> have a radius of about 1.0 inch as a result of the contoured regions <b>74</b>-<b>77</b> on the workpiece. In addition, due to the positioning of the projections <b>16</b> on the blade assembly <b>12</b> shown in <figref idref="DRAWINGS">FIG. 12</figref>, and the similar positioning of the projections <b>26</b> on the blade assembly <b>22</b>, the upper left and right corners and the lower left and right corners of the block <b>100</b> at the radiused sections <b>114</b>, <b>116</b> are removed during the splitting process.

The radiused sections <b>114</b>, <b>116</b> serve several purposes. First, they present a more rounded, natural appearance to the block, as compared to a block in which the front face intersects the sides at a sharp angle. Second, in the case of the sharply angled block, the splitting/distressing action produced by the splitting blade assemblies described here can break off large sections of the corners, which can create fairly significant gaps in the walls. Contact between adjacent blocks in a wall is often sought in order to act as a block for back fill material, such as soil, that may seep through the wall, as well as to eliminate gaps between adjacent blocks which is generally thought to detract from the appearance of the wall. If suitable precautions, such as the placement of filter fabric behind the wall, are not used, the fine soils behind the wall will eventually seep through the wall. The use of radiused section <b>114</b>, <b>116</b> appears to minimize the corner breakage to an acceptable degree, so as to preserve better contact or abutment surfaces with adjacent blocks in the same course when the blocks are stacked to form a wall.

In the blocks of <figref idref="DRAWINGS">FIGS. 14-16</figref>, the top and bottom surfaces <b>102</b>, <b>104</b> do not have to be completely planar, but they do have to be configured so that, when laid up in courses, the block tops and bottoms in adjacent courses stay generally parallel to each other. Further, the front surface <b>110</b> of each block is wider than the rear surface <b>112</b>, which is achieved by converging at least one of the side surfaces <b>106</b>, <b>108</b>, preferably both side surfaces, toward the rear surface. Such a construction permits inside radius walls to be constructed. It is also contemplated that the side surfaces <b>106</b>, <b>108</b> can start converging starting from a position spaced from the front surface <b>110</b>. This permits adjacent blocks to abut slightly behind the front face, which in turn, means that it is less likely that fine materials behind the wall can seep out through the face of the wall. Such a block shape is shown in <figref idref="DRAWINGS">FIG. 17</figref>.

The front surface <b>110</b> of the block has a roughened, rock-like texture. In addition, an upper edge <b>118</b> and a lower edge <b>120</b> of the front surface <b>110</b> are also roughened as a result of the projections <b>16</b>, <b>26</b> on the splitting blade assemblies <b>12</b>, <b>22</b>. As a result, the front surface <b>110</b> and the edges <b>118</b>, <b>120</b> are provided a roughened, rock-like appearance. Further, the entire front surface <b>110</b> is slightly rounded from top to bottom when viewed from the side. The edges <b>118</b>, <b>120</b> are also rounded.

<figref idref="DRAWINGS">FIGS. 14 and 16</figref> also illustrate the radiused sections <b>114</b>, <b>116</b> and at least a portion of the side surfaces <b>106</b>, <b>108</b> as being lightly textured. The light texturing is achieved using a horizontal groove or channel that is formed in the mold walls at the locations where light texturing on the workpiece and resultant block is desired.

<figref idref="DRAWINGS">FIG. 19</figref> illustrates a portion of a mold wall <b>117</b> from the mold <b>84</b> in <figref idref="DRAWINGS">FIG. 13</figref> having a generally horizontal channel or groove <b>119</b> provided in the wall close to the bottom of the wall. <figref idref="DRAWINGS">FIG. 20</figref> is a cross sectional view of the wall <b>117</b> showing the shape of the channel <b>119</b>. The mold wall <b>117</b> corresponds to one of the surfaces of the block that is to be lightly textured, such as the side surface <b>106</b>. The channel <b>119</b> is illustrated as extending along a portion of the wall <b>117</b>, in which case light texturing of only a portion of the corresponding surface of the workpiece will occur. However, the channel <b>119</b> can extend along the entire length of the wall <b>117</b> if light texturing is desired along the entire corresponding surface.

The channel <b>119</b> is illustrated as being rectangular in cross section. However, other shapes can be used such as semi-circular, v-shaped, or ear-shaped, and multiple grooves or channels can be used. These multiple grooves or channels can be at the same or different heights on the mold wall. The channels may be generally parallel to the bottom of the mold or they may be skewed or even non-linear such as serpentine. Criss-cross patterns can be used. The channel <b>119</b> preferably has a height of about 0.50 inches, a depth of about 0.060 inches, and the channel <b>119</b> begins about 0.090 inches from the bottom of the wall <b>117</b>. Other channel dimensions, in addition to channel shapes, could be used, with variations in the resulting light texturing that is produced.

It has been discovered that the provision of the channel <b>119</b> causes texturing of the corresponding surface of the molded workpiece as it is discharged from the mold. Although not wishing to be bound to any theory, it is believed that some of the fill material used to form the workpiece temporarily resides in the channel <b>119</b> during the molding process. This is referred to as “channel fill material”. As the compressed and molded fill material is discharged from the mold cavity, this channel fill material begins to be disturbed or disrupted by the movement of the workpiece within the mold cavity and the channel fill material is caused to tumble or roll against the passing surface of the workpiece, imparting a slightly rough texture to it. It seems likely that the channel fill material is constantly being changed/replenished as the workpiece passes by the channel during discharge of the workpiece from the mold. Regardless of the mechanism, the surface of the passing workpiece is given a slightly rough texture by this process.

Further details on molds and grooves or channels in mold walls to achieve texturing can be found in co-pending U.S. patent application Ser. Nos. 09/691,931 and 09/691,898, each of which was filed on Oct. 19, 2000, and which are incorporated herein by reference in their entirety.

Preferably, at least the radiused sections <b>114</b>, <b>116</b> and the front portion of the side surfaces <b>106</b>, <b>108</b> are lightly textured. This is important because the roughening caused by the projections <b>16</b>, <b>26</b> can expose portions of the block sides when the blocks are laid up in a wall. The light texturing of these side surfaces has the effect of disguising the manufactured appearance of the exposed portions of the blocks. If no light texturing is employed, then the generally smooth, somewhat shiny sides of the blocks tend to look very manufactured. It is preferred that the light texturing be produced along about 3.0 to about 8.0 inches of each block side, extending over each radiused portion and a portion of each side surface, as measured from the front surface of a 12 inch long block. However, it is contemplated and within the scope of the invention to lightly texture more of the side surfaces than just the front portions thereof, including the entirety of the side surfaces, and to lightly texture the rear surface <b>112</b>.

The material used to form the masonry block <b>100</b> is preferably a blended material to further add to the natural, weathered rock-like appearance. As is known in the art, fill materials that are used to make blocks, bricks, pavers and the like, contain aggregates such as sand and gravel, cement and water. Fill materials may contain pumice, quartzite, taconite, and other natural or man-made fillers. They may also contain other additives such as color pigment and chemicals to improve such properties as water resistance, cure strength, and the like. The ratios of various ingredients and the types of materials and sieve profiles can be selected within the skill of the art and are often chosen based on local availability of raw materials, technical requirements of the end products, and the type of machine being used.

Preferably, the fill material that is used to form the block <b>100</b> is formulated to produce a blend of colors whereby the resulting front face <b>110</b> of the split block <b>100</b> has a mottled appearance so that the front of the block simulates natural stone or rock. For instance, as shown in <figref idref="DRAWINGS">FIG. 14</figref>, the front face <b>110</b> has a mottled appearance produced by a plurality of colors <b>122</b>, <b>124</b>. One or more additional colors could be added in order to alter the mottled appearance. However, in instances when a mottled appearance is not desired, a single color fill material or a natural aggregate mix could be used.

When a mottled appearance is sought, the fill material that is used to form the workpiece and thereby the resulting block(s) is preferably introduced into the mold using a divided gravity hopper and a feedbox, which are known in the art, above the mold. <figref idref="DRAWINGS">FIG. 21</figref> shows a top view of a hopper <b>170</b> and a partition plate <b>172</b> that is mounted in the hopper <b>170</b> to help produce a swirling of colors in the fill material. The partition plate <b>172</b> extends across the width of the hopper <b>170</b>, with the edges of the plate <b>172</b> being removably disposed within channels <b>174</b>, <b>176</b> formed on the hopper to enable removal of the plate <b>172</b>. The plate <b>172</b> also extends vertically within the hopper <b>170</b>.

The plate <b>172</b> is comprised of an arrangement of baffles <b>178</b> that are intended to randomly distribute each fill material color as it is poured into the hopper <b>170</b>. Each fill material color is poured separately into the hopper, with the plate <b>172</b> randomly distributing each color onto any material previously poured into the hopper. The sucking action of the feedbox on the hopper as fill material is discharged into the feedbox further contributes to a random distribution of the various colors in the fill material. Moreover, an agitator grid, which is known in the art, is present in the feedbox for leveling the fill material. The action of the agitator grid also contributes to the swirling of the colors in the fill material.

The fill material with the randomly distributed or swirled colors is then transferred from the feedbox into the mold to produce the workpiece. The swirling of the colors in the fill material produces the mottled appearance on the front surface of the block <b>100</b> once the workpiece is split. The swirling produced by the plate <b>172</b>, the sucking action of the feedbox, and the agitator grid is random, so that the swirling of colors in each workpiece and the resulting mottled appearance on each block, is generally different for each workpiece and block formed. In addition, the mottled appearance of the front surface will vary depending upon where the workpiece is split due to the random swirling of the colors in the workpiece.

An example of a composition, on a weight basis, of one fill material that can be used to produce a mottled appearance using a 3-color blend is as follows:

<tables id="TABLE-US-00001" num="00001"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="4"><colspec colname="offset" colwidth="42pt" align="left" /><colspec colname="1" colwidth="49pt" align="center" /><colspec colname="2" colwidth="63pt" align="center" /><colspec colname="3" colwidth="63pt" align="center" /><thead><row><entry /><entry namest="offset" nameend="3" align="center" rowsep="1" /></row><row><entry /><entry>Gray (½ batch)</entry><entry>Charcoal (½ batch)</entry><entry>Brown (½ Batch)</entry></row><row><entry /><entry namest="offset" nameend="3" align="center" rowsep="1" /></row></thead><tbody valign="top"><row><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="4"><colspec colname="1" colwidth="42pt" align="left" /><colspec colname="2" colwidth="49pt" align="char" char="." /><colspec colname="3" colwidth="63pt" align="char" char="." /><colspec colname="4" colwidth="63pt" align="char" char="." /><tbody valign="top"><row><entry>Sand</entry><entry>2500</entry><entry>2500</entry><entry>2500</entry></row><row><entry>Buckshot</entry><entry>1000</entry><entry>1000</entry><entry>1000</entry></row><row><entry>Cement</entry><entry>275</entry><entry>275</entry><entry>275</entry></row><row><entry>Flyash</entry><entry>100</entry><entry>100</entry><entry>100</entry></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="1"><colspec colname="1" colwidth="217pt" align="center" /><tbody valign="top"><row><entry>Additives:</entry></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="4"><colspec colname="offset" colwidth="42pt" align="left" /><colspec colname="1" colwidth="49pt" align="center" /><colspec colname="2" colwidth="63pt" align="center" /><colspec colname="3" colwidth="63pt" align="center" /><tbody valign="top"><row><entry /><entry>RX-901 19 oz.</entry><entry>RX-901 19 oz.</entry><entry>RX-901 19 oz.</entry></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="1"><colspec colname="1" colwidth="217pt" align="center" /><tbody valign="top"><row><entry>Color:</entry></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="4"><colspec colname="offset" colwidth="42pt" align="left" /><colspec colname="1" colwidth="49pt" align="center" /><colspec colname="2" colwidth="63pt" align="center" /><colspec colname="3" colwidth="63pt" align="center" /><tbody valign="top"><row><entry /><entry>No color added</entry><entry>Black 330 3.75 lbs.</entry><entry>Red 110 5.10 lbs</entry></row><row><entry /><entry /><entry /><entry>Black 330 5.10 lbs</entry></row><row><entry /><entry namest="offset" nameend="3" align="center" rowsep="1" /></row></tbody></tgroup></table></tables>

RX-901, manufactured by Grace Products, is a primary efflorescence control agent that is used to eliminate the bleeding of calcium hydroxide or “free lime” through the face of the block.

Other fill material compositions could be used as well depending upon the desired mottled appearance of the block front face, the above listed composition being merely exemplary. For instance, a two-color fill material could be used.

Once the fill material has been prepared, it is transported to the block forming machine, and introduced into the mold in the commonly understood fashion. The block forming machine forms “green”, uncured workpieces, which are then transported to a curing area, where the workpieces harden and gain some of their ultimate strength. After a suitable curing period, the workpieces are removed from the kilns, and introduced to the splitting station, adapted as described above, where the workpieces are split into individual blocks. From the splitting station, the blocks are transported to a cubing station, where they are assembled into shipping cubes on wooden pallets. The palletized cubes are then transported to an inventory yard to await shipment to a sales outlet or a jobsite.

The block <b>100</b> also includes a locator lip or flange <b>126</b> formed integrally on the bottom surface <b>104</b> adjacent to, and preferably forming a portion of, the rear surface <b>112</b>. The lip <b>126</b> establishes a uniform set back for a wall formed from the blocks <b>100</b>, and provides some resistance to shear forces. In the preferred configuration, the lip <b>126</b> is continuous from one side of the block <b>100</b> to the other side. However, the lip <b>126</b> need not be continuous from one side to the other side, nor does the lip <b>126</b> need to be contiguous with the rear surface <b>112</b>. A different form of protrusion that functions equivalently to the lip <b>126</b> for locating the blocks could be used.

The block shape shown in <figref idref="DRAWINGS">FIGS. 14-16</figref> is preferred. However, it is contemplated and within the scope of the invention to utilize the concepts described herein, including the roughened edges produced by the projections <b>16</b>, <b>26</b>, and/or the light texturing of the side surfaces, and/or the mottled appearance of the front surface, on other block shapes. In addition, the block <b>100</b> could be formed with internal voids to reduce the weight of the block <b>100</b>.

For example, <figref idref="DRAWINGS">FIG. 17</figref> illustrates a block <b>150</b> that is provided with a roughened front face <b>152</b> with roughened edges <b>152</b><i>a</i>, <b>152</b><i>b</i>, light texturing of a portion of side surfaces <b>154</b>, <b>156</b> (only one side surface <b>154</b> and the light texturing thereon is visible in <figref idref="DRAWINGS">FIG. 16</figref>), and a mottled coloration of the front face <b>152</b>. Like the block <b>100</b>, the entirety of the side surfaces <b>154</b>, <b>156</b>, as well as a rear surface <b>158</b>, could be lightly textured. The block <b>150</b> is preferably split from a suitable workpiece using the splitting assemblies <b>12</b>′ and <b>22</b>′ of <figref idref="DRAWINGS">FIGS. 11 and 8</figref>, respectively. The general shape of the block <b>150</b> is similar to that disclosed in FIGS. 1-3 of U.S. Pat. No. 5,827,015. Other block shapes could be provided with one or more of these features as well.

In the preferred embodiment, the block <b>100</b> is one of a pair of blocks that results from splitting a workpiece, such as the workpiece <b>68</b> in <figref idref="DRAWINGS">FIG. 12</figref>, using splitting blade assemblies of the type illustrated in <figref idref="DRAWINGS">FIGS. 8 and 11</figref>. Different block sizes can be formed by reducing or enlarging the size of the workpiece from which the blocks are produced. However, as discussed above with respect to <figref idref="DRAWINGS">FIG. 10</figref>, the workpiece <b>58</b> could be formed and then split to produce three different block sizes, each of which is similar to the block <b>100</b>. In addition, it is contemplated and within the scope of the invention that a single one of the blocks <b>100</b> could be formed from a workpiece that, after splitting, results in a waste piece in addition to the block <b>100</b>.

<figref idref="DRAWINGS">FIG. 18</figref> illustrates a wall constructed from three differently sized blocks, with each block having a configuration similar to the block <b>100</b>.

There may be instances when it is satisfactory that a block be provided with only one roughened edge on the front face. Therefore, it is contemplated and within the scope of the invention that a workpiece could be split using a single one of the splitting assemblies described herein.

The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.